Psalm 139 shows the complete exercise of heart that belongs to
God's ways. Though the faithfulness of God perfects all His purposed
blessing, not a thought escapes God. There is, morally speaking, no
staying in His presence; but there is no getting out of His
presence, nor where He sees not, though conscience might be glad to
flee. But this brings in another aspect. He knows all, because also
He has formed all. This connects us with the taking perfect notice
of us in goodness. He cares for us, watches over every member that
is formed, as He knows our every thought; if He does, He has His own
too, and these are precious to us. This is just the change and
working of faith. It begins necessarily by conscience under God's
eye; for it brings us into His presence, and then gets at God's
thoughts, who has formed us for Himself, and then unfolded boundless
spheres of His own blessing and ways. God watches over him in the
silence of sleep: waking, therefore, he finds himself with God.

But, further, this connection with God is a perfect breaking
with the wicked: God will slay them. And he calls on them to depart
from him. Therefore he looks at the wicked with horror, because of
what they are to God for himself, that he may be searched
throughout, that no wickedness may remain in him. This psalm goes
far in the relationship of man's spirit with God, though it looks to
the external judgment of the wicked and uses language which becomes
verified in the assembly figuratively, and which is so also in the
resurrection. The great direct point in it is the full searching out
of man's heart, as it will be then, as it must be ever. But this
searching, when we are under our own responsibility, is, Whither
shall I flee from Him? But when we are God's workmanship (that is,
when grace and power have come in), God's thoughts become precious
to us, and we can ask to be searched, known, and tried the more the
better, that, emptied of self, we may be able to enjoy God. Then
also we look for leading. The will is broken, as the thoughts are
judged, and our desire is to be led of God. We see at the same time
the character of the psalm connects it with the latter day. "Surely
thou wilt slay the wicked." It looks for judgment, and has hatred
and horror of the haters of God.